A distinction must be made between use of the present invention in primary and secondary fermentation processes involved in wine making and in aging of the wine after fermentation has been completed.
In conventional wine making, after the grapes have been washed with, say sulfur dioxide they are passed through the stemmer-crusher where they are desteamed and crushed. The resulting "must" is transferred to a separation tank. Next, the "free running" juice is separated from the skin and seeds in the presence of nitrogen. Then the free-running juice is racked within a fermentation tank and is allowed to begin fermentation by the introduction of starter yeast. (The separated seeds and skins are also removed and re-processed via a wine press to provide pressed wine juice and pumice, the latter being discardable at a dump site.) Within the fermentation tank, temperature is controlled by means of a heat exchanger jacketed at the exterior of the tank to control the rate of fermentation. A vent valve/air lock assembly allows escape of oxidation gases from the tank while simultaneously preventing entry of ambient air back into the tank. After a time, fermentation is complete, and the resulting wine is emptied into a series of barrels through a filling wand or spicket where secondary fermentation and/or aging begins. In both of these circumstances, injection of a nitrogen cap usually proceeds the filling operation. In the former situation, the barrel can also be fitted with a vent/air lock assembly. In the latter, the wine is sampled from time-to-time using a thief tube. (Moreover, if primary barrel fermentation is to occur akin to champagne bottle fermentation processes, the barrel must be first fitted with a similar vent/air lock assembly. After fermentation is completed, sampling follows).
While solid stoppers formed of FDA approved silicone rubber are available for releasably sealing wine barrels, such stoppers heretofore have not been provided with central openings or with integrally attached auxiliary plugs. Hence, sampling of the wine after fermentation, has to occur with the stopper removed and a thief tube inserted into the barrel. Then the stopper is re-inserted. Eventually friction forces can erode enough of the surface of the stopper to prevent proper sealing and permit ambient air and external bacteria (enemies of good wine makers) to enter the barrel and attack the wine.
When fermentation is occurring, the vent valve/air lock assembly previously mentioned, is used. This requires purchasing solid stoppers and then modifying them with an opening for the valve/air lock assembly. Often the opening is too large, allowing the stopper too much flexibility to properly seat within the bunghole. Eventually, the modified drilled stopper must be removed and replaced by a conventional solid stopper. Since there are many hundreds of barrels within even small wineries, under-ordering or over-ordering of solid stoppers is a common occurrence. Additional follow-up purchases are often needed. In addition, on-site modifications are expensive and time consuming. Further, the re-manufactured stoppers eventually have to be replaced as aging of the wine begins. Accordingly, there is a need to provide a barrel stopper formed of an FDA approved elastomer but configured so that after sealing just once to the bunghole of the barrel, attendant wine making processes can be ac without the inserted stopper having to be removed, either to accommodate a vent valve/air lock assembly or for inserting a thief tube for sampling purposes.